A former paratrooper reduced to tears by the stress of working as a manager with the Royal Mail has won his case for unfair dismissal.

Colin Richardson, of Ingleby Barwick, was sacked after nearly 22 years' service for shouting and swearing at a subordinate who insulted him during a "flashpoint" incident.

A Royal Mail internal investigation reported that Mr Richardson "had a position of trust and responsibility and to swear at an employee under any circumstances was totally unacceptable, both professionally and socially".

But an employment tribunal found that the line manager, at the Royal Mail's Stockton sorting office, had "acted under provocation at a time when he was showing untypical behaviour as a result of workplace stress".

The claimant told the Thornaby tribunal that managers had been under pressure to make savings in overtime budgets. But with "insufficient staff" this left him and his team to "pick up a disproportionate amount of work".

Minutes before the incident, in February 2006, Mr Richardson was seen by a colleague and friend sitting in his car in tears.

The 47-year-old married father-of-one told the tribunal he had broken down because he felt he could not cope. Ten minutes later he was embroiled in the heated conversation that would lead to him being sacked.

It was the unanimous judgement of the tribunal that Mr Richardson's claim of unfair dismissal was "well founded".

It said the investigation into the incident was "flawed" adding: "A proper investigation would have revealed the claimant had taken sick leave two years earlier, having been diagnosed with work-related stress.

"The claimant had complained to his line manager the day before the incident of overwork and his line manager had treated him in an entirely inappropriate and sarcastic way. To draw the conclusion that stress was 'in no way an explanation for Mr Richardson's behaviour', in the circumstances of this case was perverse."

Mr Richardson said after the judgement: "I have cleared my name and have closure now.

"But we had to sell our house and move to a smaller one, and I now work in a supermarket. But I'd like to get back into management. I've had lots of postmen supporting me, but the Royal Mail have never once showed remorse."

Compensation is to be decided, but the tribunal said it will be reduced by 10% as the claimant should not have used abusive and threatening language, "even under provocation and when ill with stress".